Manufacture of mixed resins for cation exchange



Patented Nov. 9, 1943 MANUFACTURE OF MIXED RESINS FOR CATION EXCHANGE Hans Wassenegger, Deosan in Anhalt, Germany;

' vested in the Alien Property Custodian No Drawing. Application January 31, 1939, Se-

rial No. 253,777. In Germany February 8,

4 Claims.

The present invention relates to new artificial resins which have cation-exchanging properties.

It is known that artificial resins derived from polyoxybenzenes and aldehydes, particularly formaldehyde, when they have been produced under special conditions have the property of exchanging cations in aqueous saline solutions. The exchange properties and the capacity for exchange at a given pH-value are in high degree dependent on the. kind and the number of the groups having a tendency to exchange. Many phenol resins have a commercially useful exchange efiect merely in alkaline medium, since they contain only OH-groups as acid residues; their exchange capacity inan acid medium is insuflicient.

On the other hand, compounds having strong acid groups capable of imparting a strong capacity for splitting neutral salts and also a satisfactory exchange in acid medium are in general only suitable for use to a limited extent for pro-' ducing formation of resins having the necessary physical properties for use in exchange filters.

Such compounds are amino-, oxyor aminohydroxy-sulphonic acids of the naphthalene series, for example:

1-amino-naphthalene-3-sulphonic acid 1-amino-naphthalene-5-sulphonic acid l-amino-naphthalene-Zz-disulphonic acid l-amino-naphthalene-3 fi-disulphonic acid 1 -amino-naphthalene-3 B-disulphonic acid l-amino-naphthalene-3 6 8-trisulphonic acid 1 -amino -naphthalene-4 6 S-trisulphonic acid 2-amino-naphthalene-6-sulphonic acid 2-amino-naphthalene-3:6z8-trisu1phonic acid 7 2-amino-naphthalene-4 :6 8-trisulphonic acid 1-hydroxy-naphthalene-5-sulphonic acid l-hydroxy-naphthalene-S-sulphonic acid 1-hydroxy-naphthalene-3 B-disulphonic acid l -hydroxy-naphthalene-3 6 8-trisulphonic acid 1 8-dihydroxy-naphthalene-3 B-disulphonic acid Z-hydrQxy-naphthaIene-S B-disulphonic' acid 2-hydroxy-naphthalene-6 8=disulphonic acid 2-hydroxy-naphthalene-3 6 8-trisulphonic acid 1 -hydroxy-8-amino-naphthalene-3 6 -disulphonic acid 4-hydroxy-2-amino naphthalene 8 sulphonic acid The present invention relates to the manufacture of valuable exchange bodies from the aforesaid parent materials having strongly acid groups by condensing them with an aldehyde, especially formaldehyde or its equivalent in admixture with other compounds which are capable of forming good resins with aidehydes, especially formaldehyde. Such other compounds, which need not of themselves yield exchange bodies, are, for example, the monoand polyhydroxy-benzones and their derivatives as well as urea, thiourea and their derivatives or preliminary condensation products. The term a phenol as used in the claims is to be construed as covering both monoand polyhydric phenols.

By this mixed condensation and subsequent cautious drying there are obtained resin gels which combine the good properties of the resin former with the exchange activity of the other components. In this manner the final body unites the insolubility, stability towards acid and dilute alkalies, the stability of form and a suitable resistance to swelling with high capacity for splitting neutral salts and high exchange capacity.

The following examples illustrate the invention, the parts being by weight:

Example 1 Into a solution of 1100 parts of resorcinol and 500 parts of sodium-1:B-dihydroxynaphthalene- 3:6-disulphonate in 2000 par'tsof water, which solution has been made alkaline to methyl-orange by means of caustic soda lye, are introduced,

sodium salt of 2-amino-4-naphthol-6:S-disulwhile stirring, at 15 C. 1800 parts of formaline of 30 per cent strength. The temperature of the mixture rises spontaneously to about 90 C. and the mixture solidifies. The jelly produced is dried at 80 C. and constitutes a resin with a capacity for 16 grams of CaO per litre when used for softening water.

Example 3 parts of resorcinol and 15 parts of the phonic acid are dissolved together with 6 parts by volume of concentrated caustic soda solution in 77 parts of water and mixed with 67 parts of takes up 27.5 grams oi CaO upon filtration with a 10 per cent. neutral solution of calcium chloride until the solution passes the filter.

Example 4 To a solution of 165 parts of resorcinol, 75 parts of the sodium salt of 1-amino-8-naphthol- 3:6-dis'ulphonic acid and 30 parts by volume of concentrated caustic soda solution in 200 parts of water there are added at 20 C. 240 parts of formaline of 30 per cent strength. The solution solidifies with the evolution of heat to a Jelly, which is dried at 85 C. and is then broken up. 1 kilo of the material, when used as a hydrogen ion exchanger, takes up 26.5 grams of CaO upon filtration with a 10 per cent neutral solution of calcium chloride until the solution passes the filter.

Example 5 To a solution of 22 parts of resorcinol, 8 parts of the sodium salt of 1-naphthol-3z8-disulphonic acid and 3 parts by volume of concentrated caustic soda solution in 34 parts of water there are added at 25 C. 32 parts of formaline of 30 per cent strength, whereupon the mixture with evolution of heat solidifies to a 'jelly. As described under Example 3, the product is dried and broken up. 1 kilo of the material, when used as a hydrogen ion exchanger, takes up 19.2 grams of CaO upon filtration of a per cent neutral solution of calcium chloride until the solution passes the filter.

Example 6 100 parts of phenol, 27 parts of the sodium salt of 1:8 dihydroxynaphthalene 3:6-disulphonic acid and 20 parts of concentrated caustic soda solution are dissolved in 100 parts of water. The solution is boiled with 200 parts of formaline of 30 per cent strength and after subsequent solidification is kept for 18 hours at 80-100 C. After drying and comminution as described under Example 3, 1 kilo of the material, when used as a hydrogen ion exchanger, takes up 27.8 grams of C80 upo filtration of a 10 per cent. neutral solution of calcium chloride until the solution passes the filter.

Example 7 500 parts of phenol, 200 parts of the sodium salt of 1-naphthol-3z8-disulphonic acid and 8 parts of concentrated caustic soda solution are heated with 500 parts of water to 45 C. After the addition of 900 parts of formaline of 30 per cent strength the mixture is slowly heated and finallyboiled until a' jelly is formed, which is kept at 80-l00 C. for a further hours. As described under Example 3, the product is dried and comminuted, and takes up per kilo 28.7 grams oi CaO, when used as a hydrogen ion exchanger, upon filtration of a 10 per cent. neutral solution of calcium chloride until the solution passes the filter.

The absorption capacities of the products of Example 3 to Example 7 is determined as follows:

The products are swollen in water and then allowed to stand for hour in hydrochloric acid (1:1). Then a neutral solution of calcium chloride of 10 per cent strength is filtered over until no more calcium is absorbed by the resin. This can readily be recognised by the originally acid filtrate becoming neutral. The charged resin is washed free from chlorine and regenerated with a solution of common salt of 10 per cent. strength. The calcium thereby exchanged is then determined.

Y'Ekrample 8 1100 parts of resorcinol, 440 parts of the sodium salt of l-amino-naphthalener-6:B-disulphonic acid are dissolved together with 100 parts by volume of concentrated caustic soda solution in 1000 parts c2 water and 1700 parts of formaline of 30 per cent. strength are added at 20 C. The solution becomes warm and solidifies to a jelly which is dried at 80-l00 C. After comminution to a size of 0.5-4.5 mm. diameter the material when used as a neutral exchanger takes up about 12 grams of CaO per litre.

Example 9 425 parts of the sodium salt of 2:3:8-trihydroXy-naphtha1ene 6-sulphonic acid and 330 parts of resorcinol are dissolved together with parts by volume of concentrated caustic soda solution in 600 parts of water and 750 parts of formaline of 30 per cent. strength are added at 20 C. The resulting Jelly is dried at 80-90 C. and may be charged after comminution with about 14 parts of CaO per litre.

Example 11 1100 parts of resorcinol, 400 parts of the sodium salt of 1-amino-naphthalene-5:7-disulphonic acid and parts by volume of concentrated caustic soda solution are dissolved in 1700 parts of water and 1600 parts of formaline or 30 per cent. strength are added at 20 C. The resulting jelly is worked up in the usual way. The material may take up about 10 g. of CaO per litre.

Example 12 1100 parts of resorcinol, 300 parts of the sodium salt of 1:8-dihydroxy-naphthalene-2:4-disulphonic acid and 50 parts by volume of concentrated caustic soda solution are dissolved in 1. The process of preparing cation-exchanging resins which comprises condensing in an alkaline solution amember of the group consisting of an amino-, hydroxyand amino-hydroxy-s'ulphonic.

acid of the naphthalene series and a phenol with" formaldehyde, while using at least 2 mols of the phenol for each mol of the naphthalene sulfonic acid, the amount of the phenol not being so high as to impair the utility of the resin in acid media. the resin formation being carried so far thatthe final product is insoluble in water, acids and dilute alkalis.

2. The process of preparing cation-exchanging resins which comprises condensing in an alkaline solution a member of the group consisting of an amino-, hydroxyand amino-hydroxy-sulphonic acid of the naphthalene series and a phenol with formaldehyde, while using at least 2 mols of the phenol for each mol of the naphthalene-sulfonic acid, the amount of the phenol not being so high as to impair the utility of the resin in acid media, the resulting jelly being carefully dried so that the gelstructure is maintained.

3. The process of preparing cation-exchanging resins which comprises condensing in an alkaline solution l-hydroxy-naphthalene-ii:8-disulphonic acid and phenol with formaldehyde, while using at least 2 mols of the phenol for each mol of the naphthalene sulfonic acid, the amount of the phenol not being so high as to impair the utility of the resin in acid media, the resin formation being carried so far that. the final product is insoluble in water, acidsand dilute alkalis.

4. Artificial resins obtained according to claim 1 having cation-exchanging properties in alkaline and acid media.

HANS WASSENEGGER. 

